Abstract:

Objective To investigate the relationship between serum bilirubin and diabetic nephropathy (DN) in patients with type 2 diabetes mellitus (T2DM). Methods The clinical data of 461 patients with T2DM (T2DM group) were collected, and biochemical parameters such as fasting blood glucose, liver and renal function and blood lipid profile were recorded. Patients in T2DM group were subdivided into normal albuminuria group (NA group, n=221), microalbuminuria group (MA group, n=191) and overt albuminuria group (OA group, n=49) according to albumin to creatinine ratio (ACR). Besides, 301 healthy people were served as controls. Results The levels of serum total bilirubin (TBIL) and direct bilirubin (DBIL) in T2DM group were significantly lower than those in control group, and the differences still existed after adjustment of other influencing factors (P<0.01, P<0.05). The levels of serum TBIL and DBIL were highest in NA group and lowest in OA group, and there were significant differences among NA group, MA group and OA group (P<0.01). Patients in T2DM group were divided into three groups by the quartile of serum TBIL, and it was revealed that ACR decreased with serum TBIL (P<0.01) while glomerular filtration rate increased with serum TBIL (P<0.05). Multiple stepwise regression analysis indicated that TBIL was independently associated with ACR (β=－0.15, P<0.01). Conclusion Serum bilirubin is a protective factor in the onset and development of DN in patients with T2DM.

Key words: diabetic nephropathy, serum bilirubin, type 2 diabetes mellitus